Electric welding system.



D. H. WILSON. ELECTRJC WELDING SYSTEM. APPLICATION FILED DEC. 31,1914- RENEWED FEB. 24.1916.

IJWAW. Patented June 13, 1916.

DAVID H. WILSON, 0F PATERSON, NEW JERSEY.

ELECTRIC WELDING SYSTEM.

Specification of Letters Ilatent.

Patented June 13, 1916.

Application filed December 31, 1914, Serial No. 879,953. Renewed February 24, 1916. Serial No. 80,123.

To all whom it may concern-.-

Be it known that I, DAVID H. WILSON, citizen of the United States, and resident of Paterson, in the county of Passaic and State of New Jersey, have invented certain newv anduseful Improvements in Electric WVelding Systems, of which the following is a specification.

My invention relates to electric welding circuits.

It consists primarily of meansfexterior of the welding circuit before the arc terminals are brought into contact, introduced into the circuit with said terminals when they are brought into contact for the purpose of limiting the current to such an amount as will make the drawing of the are possible and yet avoid the spattering of metal. 7

It consistsfurther of means to regulate the current, to compensate for the variable resistance of the arc due to the unsteadiness of the operators hand, this means being introduced into the welding circuit after a sufficient period has elapsed to cover the drawing of the are by the operator.

In the drawings:.the figure shows a diagram of the circuits of my system.

My invention includes a circuit for drawing an arc, and one for regulatin the welding current, in multiple. The ormer cir cuit is traced from a source of welding current 1 through conductors 2 and 3, normally bridged contacts 4, conductor 5, magnet 6, conductor 7 tothe welding tool or terminal 8, preferably carrying the usual metal welding pencil 9 adapted to be brought into contact with a piece of work 10 which'may be a portion of fractured machinery or any other device adapted to be electrically welded.- This terminal 10 is connected through the conductor 11 backto the positive terminal of the generator 1. The magnet or electroresponsive "device 6 acts as a circuit breaker to open the short-circuit 3 around the resistance 19. When the current is established at the tool 9 and the short circuit 3 is opened, the resistance 19 serves to limit the current supplied to the tool for starting the arc. The other circuit is traced through the conductor 13 to the solenoid 14 and the.

carbon pile 15. The lever 30 under the in fluence of the compression spring 31, as shown, normally exerts a pressure upon the carbon pile to reduce its resistance and the solenoid when actuated by a current exerts an opposing force tothe spring to increase the resistance of the pile.

The circuit breaker magnet is adapted to exert a pull upon the lever 16 against the influence of the tension spring 17. When this pull 1s exerted, the lever 16 at once pulls the .bridge 18 of the circuit breaker away from linked to the bridge by the lost motion connection 23. This lost motion connection permits the bridge 18 to instantly leave the contacts 4 but causes it thereafter to travel slowly until it has bridged the contacts 21.

The lost motion connection consists of a rod 24 linked to the bridge 18 and passing through a hole 25, in the yoke'26 and provided with lugs 27 to engage the yoke. A spring 28 restores the yoke to normal position and the relief valve 29 permits rapid restoration which occurs when the arc is broken and the magnet 6 is deenergized.

When the bridge 18 closes the circuit between the contacts 21 it introduces into the circuit with the welding toolthe carbon pile welding arc to vary in length, thereby varying its resistance. This varies the amount of current that'flows across the arc and this variation of the current flow causes porosity in the weld. My carbon pileand solenoid prevent this porosity by limiting the current to an even amount, in spite of the variation in the resistance of the arc. When the arc increases in length, its resistance is increased so that a, smaller amount of current flows through the solenoid 14 which is thus weak-' ened and opposes less force to the compression spring 31 which thereupon exerts a greater compression upon the carbon-pile. This has the result of reducing the resistance of the carbon pile to offset the increase of resistance in the welding arc. The reverse of this operation is also true. The regulation of the current takes place between such narrow limits that the current is approximately uniform in its value.

In operation, the pencil 9 is brought into contact with the work 10, current traverses conductors 2, 3' and 5 and operates magnet 6 to open the short-circuit 3, thereby introducing the resistance l9 to prevent a too great flow of metal and to prevent spattering. After the arc is drawn, the pile and solenoid regulate the-flow of current to an even amount.

l Vhat I claim is 1., In combination in a welding system, a circuit comprising a source of electro-motive force and two terminals, one of which is manually operable and between which an arc may be drawn, means introduced into said circuit after said terminals are brought into contact to prevent a too great vflow of current across said terminals, and a circuit controller adapted to automatically regulate the current across said terminals after the drawing of the are. I

2. In combination in a welding system, a circuit comprising a source of electro-motive force and two terminals, one of which is manually operable and between which an are may be drawn, means introduced into said circuit after said terminals are brought into contact to prevent a too great flow of current across said terminals, and a circuit controller adapted'to automatically regulate the current across said terminals after the drawing of the are and means to automatically restore said circuit to its original condition on the rupture of said arc. V

3. In an electric welding system, a source of electro-motive force and two terminals, one of which is manually operable and between which an arc is adaptedto, be drawn for welding, a resistance normally out of said circuit and introduced into said circuit after said terminals are brought into contact and adapted to automatically vary the resistance of the circuit exclusive of the are substantially inversely proportional to the resistance of the arc.

4. In a welding system, a source of electro-motive force, and two terminals, one of which is manually movable and between which an arc is adapted to be drawn, means adapted to be introduced into said circuit when said terminals are brought into, contact, to supply a limited amount of current suitable for establishing an arc and additional means introduced. into said circuit after said terminals have been brought into contact and after the arc has been drawn adapted to automatically vary the resistance'of the Welding circuit exclusive of the arc substantially inversely proportional to the resistance of the arc.

5. In a welding system, a source of electro-motive force, and two terminals, one of which is Vman ually' movable and between which an arc is adapted to be drawn, means adapted to be introduced into said circuit when said terminals are brought into contact, to supply a limited amount of current suitable for establishing an are, additional means introduced into said circuit after said terminals have been brought into contact and after the arc has been drawn adapted to automatically vary the resistance of the weldingcircuit exclusive of the arc substantially inversely proportional to the resistance of the arc; and means to automaticallv restore said circuit to its original condition on the rupture of said arc. I

Signed at New York in the county of New York and State of New York this 2nd s5 day of'November A. D. 1914.

DAVID H. WILSON. Witnesses:

MYRON F. HILL, H. G. HOOKER. 

